Aerobic ski machine



FIG. 1 is a right side elevational view of an aerobic ski machine embodying our design the left side being a mirror image thereof;

FIG. 2 is a top plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a front elevational view thereof; and,

FIG. 5 is a perspective view thereof. 

The ornamental design for an aerobic ski machine, as shown and described. 